(1) Field of the Invention
The present invention relates to an IC card, an IC card reading/writing apparatus, a host for an IC card reading/writing apparatus, an IC card system, and a method for allowing use of multiple vendors in an IC card system.
(2) Description of the Related Art
As is well known, various kinds of cards such as cash cards, credit cards, and consultation tickets for hospitals are presently used. So called magnetic cards are generally utilized as those cards. In this case, various kinds of data such as a code number recorded on a magnetic strip of each card are read out with a magnetic head.
However, a small memory capacity of such a magnetic card restricts expansion of the functions of the card. Furthermore, since data on the magnetic strip can be easily read out, there have been several problems in terms of security, such as forgery of cards, and unauthorized use of cards.
To solve these problems, research and development have been actively carried out on IC (Integrated Circuit) cards (smart cards), which are expected to eventually replace the above-mentioned magnetic cards. In each IC card, a microprocessor and a memory are included in the form of ICs. Such an IC card generally has a storage capacity of as large as about 16-64 kbits (corresponding to about 2000-8000 characters). In contrast, a magnetic card has a storage capacity of only about 80 characters. Furthermore, in an IC card, data erasure, data writing/updating, etc. can be performed repeatedly by a built-in microprocessor.
Accordingly, an IC card can record and manage a large amount of personal information, which has been impossible to record on a magnetic card due to its small storage capacity. For example, personal information such as a clinical record can be recorded into a consultation ticket (IC card) for hospital so as to manage the personal information.
A system utilizing such an IC card includes at least IC cards and a reading/writing (R/W) apparatus for performing data reading and data writing for the IC cards. When an IC card is inserted into the R/W apparatus, the R/W apparatus reads data recorded in the IC card and/or writes data into the IC card.
For such an IC card system, various improvements have been proposed, as disclosed in Japanese Patent Application Laid-Open Nos. HEI 1-105382 and HEI 5-159118. In the system disclosed in Japanese Patent Application Laid-Open No. HEI 1-105382, a memory into which identification codes such as a manufacturer code and a manufacturing lot code have been written is mounted on the IC card (memory card). When this IC card is installed in a computer system, the IC card allows an operator to determine the state of use of the memory ICs of the entire computer system. In the system disclosed in Japanese Patent Application Laid-Open No. HEI 5-159118, information regarding a manufacturer is displayed on the surface of an IC card using symbols, a photograph, or other image information so as to prevent forgery of the card and to make it possible to visually confirm the card.
When a user constructs a system utilizing IC cards, the user generally desires to purchase IC cards and R/W apparatuses from multiple vendors so as to reduce costs.
For the IC card system as described above, a protocol for transmission with IC cards, and commands for IC cards have been standardized by ISO (International Organization for Standardization). However, since detail portions have not been standardized, the specifications of IC cards supplied by different IC card makers differ slightly from each other, which makes it quite difficult to purchase IC cards from multiple vendors.
Similarly, R/W apparatuses supplied by different makers differ from each other in their R/W commands and transmission protocols. Therefore, at the stage of designing a system, makers from which IC cards and R/W apparatuses are purchased must be determined in advance before making application programs for a host such as a personal computer. This makes it quite difficult to purchase R/W apparatuses from multiple vendors.
Due to differences in processing within IC cards, IC cards supplied from different card makers slightly differ from one another in the length of the period from the point of time when an IC card is inserted into an R/W apparatus (or when hardware reset is performed) to the point of time when the R/W apparatus receives ATR (Answer To Reset) information which is reported from the IC card to the outside when the IC card is inserted. Generally, a method has been proposed in which the maker of each IC card is identified utilizing differences in the length of the above-mentioned period, thereby allowing use of multiple vendors in the system.
However, even in this system, when a certain IC card issues ATR information with the same timing as that of another IC card supplied by a different card maker, it becomes impossible to obtain correct information regarding the card maker of the certain card. Therefore, the above-described method is not a complete solution which makes it possible to construct a system in which all the makers of cards used in the system are specified so as to allow use of multiple vendors.